Short route of internal mammary artery for coronary artery bypass graft surgery.

ABSTRACT

The muscle mammary artery (IMA) is currently the ideal conduit for coronary bypass graft surgery (CABG), due to its long-term patency rate and association with low operative mortality compared to saphenous vein grafting alone. Between January 1993 and August 1996, there were 246 patients (174 males and 72 females) that had at least one IMA utilized in CABG with this short route technique. The average number of grafts was 3.45 (range 1-6) with an average operative mortality of 1.63 per cent (four patients out of 246). The only risk factor for death was per-operatively acute myocardial infarction associated with cardiogenic shock that required an intra-aortic balloon pump. In such patients, the operative mortality was high, up to 10 per cent (three deaths out of 30 cases). It the patients had no cardiogenic shock, even when presenting with preoperative acute myocardial infarction, the operative mortality was as low as 0.46 per cent (only one death from ventricular tachycardia five days post-operatively). Associated diseases or conditions were hypertension, diabetes mellitus, hyperlipidemia, smoking chronic renal impairment, left main stenosis, low left ventricular ejection fraction (< 30 per cent) or proximal aortic calcification. None of these conditions were risk factors that contributed to post-operative death. In conclusion, this short route technique is an easy procedure, associated with a low complication and a low operative mortality. Long-term results can be expected and the method is ideal for those patients required to undergo repeated CABG, especially in the young.